Metallurgical process



Mar. 3, 1925. 1,528,267

W. E. GREENAWALT METALLURGI GAL PROCES S Filed April 1925 V 2 sneets sneet 1 Exhauster Chlorine NaCI Elecifioigzer CaOH Chlormaior Ore C11 lormaied 601 when I Lea hm Tank. wan Q Electmigzer Concentraiz.

Preclpltaie Resldue per Her

Fml

lect-goiyzer I MENTOR Electrolytic COppcr:

.l I c t em cur oruice.

METALLURGICAL PRUGEElS.

Application med c l-u e,

I! '1? all 20710122 it may concern Be it known that l, lVrLLIAM. E. GREENA- WALT, a .inp; in the city and county of Denver and State of Colorado, have invented certain new and useful. Improvements in Metallurgical PIOCGSSGS,'O$E which the following is c speci ficution. The invention is more specifically directed to the extraction of copper from its ores, espccielly from its ores containing precious and other metals.

In the treatment of lfll lptl ores by solvent i processes, it considerable dii'il'culty presented in the extraction of goli'l and silver, as .olso copper us sulphide, in a mixed oxide and sulphide ore. Gold and silverarenot-soluble in sulphate solutions ordinarily used in leechmy; copper ores, nor is the copper in its sulpense of power and :tree acid.

' phide combinations soluble in the ordinary acid solution, although it may be made soluble to considerable extent in ferric sulphate solution. Neither are gold or silver,

or copper in its sulphide combinations, up-

preciuioly soluble in chloride solutions, unless such soluiions contain ferric salts or free chlorine.

This process may coi'isidcred as a. continuation, or.modification, of that showuiu my pending application, Serial No. 380,361, tiled liiiiljf it), 1920. in the process described .in this ap talicotimi, the copper is precipitated from the solutions, preferably with the sinfiultuiieous regeneration of acid, and the lord leach solutions, prurticolly freed from copper, then electrolyzed to convert the ferrous saltiiito the ferric condition. The ferric salt so formed is produced at the TH, for ex- -smole, a. solution of "base metal, chlorides is clectrolysed, chlorine is liberated at. the anode, tliie chlorine, combining with theierroussalt, converts it into'the ferric or ion, while at the sauce time-the. acid in ti solution consumed to re-estehhsheu ci? iblillifl'i.

it frequently desirable to maintain as much acid as possible in the leech solution,

for the reason that the acid acts on idized copper in the ore, and an ecid solution of 1 lie-chloride, or chlorine,,-forexample, is more effective in chloridizing the gold and silver and copper-in its sulphide combinations, than the ox citizen of the United States, residis at neutral solution. 011' 192:2. Serial m. aces 51.

to apply chlorine gusto thesolution in'preference to electrolyzing the solutiondnect'.

It is advisable, however, to apply the to the leach solution only after the copper has been quite thoroughly precipitated. gas wereapplied to a solution containing a considerable amount of copper, much of'the chlorine would be consumed in changing the copper from the cuprous tothe cuprio conditiomend, changing it back to the cuprous condition for the purpose of precipitation. Of course, cupric chloride acts as an eilective chloridizer of the silver, but it is believed that ferric chlorideects quite as efiectively, more effectively, on both silver, and copper in some of its sulphide combinations. It 'ispreferred, therefore, in the operation of this process, to apply the chlorine to a. 'regenerthis account it frequentlybeco nes desirable If the again, there -would be a waste in,

or perhaps ated acid solution practically free from 0019- per, and necessurilyconteining a large percentage of salts of iron. i 1 In general, it. is preferred to leach the ore with a chloride solution to" extract the copper soluble in such i leach solution, until copper is fairly well extracted. The copper is precipitated from the leach solution, preferably by electrolysis, with hydrogen sulphide, or both; the precipitation should be quite complete. The regene'ated acid solution, charged with salts of iron, is separated from the resulting precipitated copper, and treated with free chlorine. The chlorine will convert the ferrous chloride into the forric chloride, and this ferric chloride act-s ef- -let-lively on the silver and residualcopper, when the solution is *applied to the ore. If there is gold in the ore, the solution is charged with an excess of, chlorine, preferably to saturation, and this free chlorine acts 95 on the gold, on the silver, The acid in the solution, resulting from the deposition, or precipitation, ofthe copper, acts to protect the chlorine, and this makes and on the copper.

copper, The copper-leach residues, assayed the so i the application of chlorinezto copper-gold wasics I oi 96.3% ofih 0.9% copper, and 1.11 oz. in gold. The tailing, after chlorine treatment, assayed 0.10% copper, and 0.02 oz. in gold, showing a total extraction of 99.5% of the copper and 98.2%

' ing, Fig. 1, which represents a flow sheet in diagrammatic section.

The ore, which may be supposed to contain copper, gold, silver, and possibly lead and other metals, is charged into the leach. ing tank and treated with an acid chloride solution. This holution will dissolve most of thecopper, but will have little or no effeet on the gold and silver. The resulting solution containing copper chloride and considerable amounts of iron chloride is flowed into the S0 reducer, where it is treated with sulphur dioxide to reduce the cupric copper to the cuprous condition and the feiric iron to the ferrous condition. The reduced solution then flows into electrolyzer .No. 1, where a portion of the copper is deposited at the cathode and an equivalent of chlorine liberated at the anode. The chlorine liberated at the anode will first combine with the excess of sulphur dioxide gas in the electrolyte, and after the excess gas is consumed the chlorine will react with the cn .prous and ferrous salts to convert them into the cupric and ferric conditions. This lat ter condition, however, is not allowed to proceed very-far, and the flow of copper solution through the cells is regulated so that only a small portion of the variable valent into the GuS reducer, where the ferric and cupric salts are reduced with concentrated copper sulphate, preferably with the precipitate obtained by precipitating the cop per from the lean solutions with hydrogen sulphide. into the electrolyzer No.2, where more copper is deposited andthe variable valent salts raised to a higher valency. As before, the

larger portion of the electrolyzed solution is returned to the Cold reducer, and then phide. The solution together with the precipitate flows into the separator, where the precipitate is separated from the solution. Ihe precipitate is conveyed to the Gus reducer, where much of the copperin the presulphide.

The reduced solution then flows cipitate is consumed in reacting, on the ferric and cupric salts, as-already described.

The depleted copper solution is flowed into the chlorinator, where it is treated with gaseous chlorine generated, from common salt, in the NaGl electrolyzer. The solution is thoroughly impregnated with the gasin the chlorinator, and this is efi'ectively accomplished by maintaining a relatively largepool of the solution in a closed chamber, adapted to contine the chlorine gas over the solution, and then, with rotary mechanism within the chamber, rotating at a high speed,

spraying the solution into the gaseous atmosphere over the solution. In this way the entire pool of solution is under continuous treatment with the gas. The lower valency salts ar again raised to a higher valency and the solution saturated with free 01110-- rine. The prepared solution then flows into the chlorinated solution tank, from which it may be drawn into the leaching tank as desired.

It is evident, that if the solution, before chlorinating, contained much copper, a great deal of chlorine would be consumed in combining with the cuprous copper to convert it into the eupric condition. and the cupric copper-would have to be reduced again preparatory to precipitation, and this would represent a loss of chlorine and precipitant. The highly chlorinated solution, applied to the ore after the larger portion of the copper has been extracted, acts energetically on the gold and the silver to convert them into the form of chlorides. The gold is readily soluble in any ordinary solution, and the silver chloride is soluble in a chloride solution.

The chlorinated. solution, issuing from the leaching tank, and containing gold, silver, some copper, and lead, it there is lead in the ore, is flowed into the hydrogen sulphide cipitated, as the sulphides, with hydrogen These sulphides are sent to they CuS reducer, where much of the copper is redissolved, and converted into the electrolytic metal, as described. The copper precipitate residue, still containing some copper, is filtered and roasted in the precipitate roasting furnace. This converts .the

. )recintator where all the metals are resulphides into the sulphates and oxides. The

roasted material is drawn into the precipitate separator tank, where sulphuric acid is applied to'it. The dilute sulphuric acid solution'dissolves the copper, as sulphate, and the copper sulphate solution may be electrolyzed to recover the copper as the (ilectrolytic metal, in eleetrolyzer No. 3. The gold, of the precipitate, is-insoluble in a sulphate solution; the silver, owing to a small amount of chloride which may be present, or added, converts the silver into the insoluble chloride, it it occurs as sulphate; the lead will er than ordinary rabble roasting, in that the labor is reduced to a minimum. The roasted material, roasted in this way wil be in the form of porous lumps. The lines will be 5 granular and quite free from dust, as roasting dust is ordinarily understood.

Cement copper is also zulvantageously roasted under these conditions. It cement copper is roasted under ordinary conditions,

the dusting will be excessive. It roasted under the conditions of this process, without rabbling in the'lirst stages of the roasting, the cement copper will acquire a set which converts it into lumps, and these lumps are quickly and completely soluble 'in dilute acid.

While the general process of converting the chemically precipitated copper into clec-- trolytic metal is not dependent upon the roasting described, it is an important step in the economical and practical application.

In the application of the general process to low grade copper ores containing other metals, leaching witha chlorine solution permits of the simultaneous extraction of all the metals, such as copper, gold, silver, and lead, and thei complete chemical precipita-ti'on, preferably as sulphides, while the roasting of the chemical precipitate and leaching of the roasted precipitate with a sulphate solution, offers aconvenient way of separating the copper from the other metals, and of obtaining exceedingly pure copper inthe electrolytic form.

If the copper ore contains silver or lead, or both, it will be desirable to use a fairly concentrated chloride solution as the leaching solvent.

If the ore contains considerable copper it will usually be desirable to first leach with a sulphate solution to extract the larger portion of the copper, while the other metal values, including the portion of the copper which is not readily soluble in a sulphate solution, remain in the residue, The residue is then treated with a chlorine solution. In this way a close extraction of the remaining metals, gold, silver, lead, and copper, can be made. The. metals are preferably precipitated together from the chloride solu- 'tion, preferably with hydrogen sulphide or metallic iron. This complex precipitate is then washed and roasted. The copper is converted into the oxide or sulphate, and in that form is readily soluble in a dilute solution of sulphuric acid, while the gold, the silver, and the lead remain insoluble. A dilute solution; of sulphuric acid is applied to the precipitate, after roasting, and this Ire-dissolves the copper as the sulphate. The resulting copper sulphate is quite pure and can be easily electrolized to deposit the copper as the pure electrolytic metal and regencrate the acid, which is cyclically used in the process This separates the copper ofthe precipitate from the other mean values, The residual precipitate is then easily treated torecover the other metals in metallic form.

In this general method of procedure in the treatment of high grade copper complex ore the copper may be electrolytically olitained from sulphate solutions or eleetrolytes, while the remaining metals may be recovered in elementaliorm, using a chloride solution as the leaching medium.

In the modified flow sheet, Fig. '2, the process may best be described by assuming, say, a copper concentrate, suitably roasted, and containing eithergold, silver, 'or lead, or all, in addition to the copper.

The copper is leached from the roasted ore or concentrate, with a chloride solution. of sufiicient strength to maintain cup ous chloride, silver chloride, and lead chloride in solution. The leach solution will, necess. sarily, contain salts of iron. The leak-h solution, as applied to the ore. will usually contain much of the iron and much of the copper in the form of cupric and ferric salts, These salts, as is well known, exert a strong chloridizing action on the metals to be extracted. Cupric chloride and ferric chloride, especially at elevated temperatures and under agitation, convert the silver and the lead into the form of chlorides, and if 9 there is gold in the ore, free chlorine in the solution Will convert the gold into the chloride. All of these chlorides,as also some of the sulphates, such as lead sulphate, are soluble in strong chloride solution The copper solution issuing from the leaching tank will, therefore, contain either silver, gold, or lead, or all three, in solution. 'Some of the copper will be in the cuprics'tate and some in the cuprous state. Some of the iron will be in the ferric state and some in the ferrous state. i

Ferric iron and cupric copper are highly injurious inv the electrolytic depositionjof the copper, and, as it is desirable to; eliniiunto the other metals from the copper solu-y tion before electrolysis, it is desirable to; Z duce the salts of the variable. valent ele-g ments preparatory to further treatinen This is done by applying sulphur'di a de: to the copper solution in the SO -rc ducrr No. 1. The sulphur dioxide reduces'the ien ric iron and the cupric copper, while an".- equivalent of acid is regenerated. The strong chloride solution maintains the cuprous chloride in solution. I I r The reduced solution is then flowed into agitator N0. 1, where it is agitated with copper precipitate.- This precipitate is pref; erably in the form of sulphide, obtained from precipitating the'copper from the lean and foul solutions with hydrogen sulphide, but it may be in some othe forn1', such as a me al precipitat optain ed either by depositing the copper i "011i lean and foul solutions:

I essee? by electrolysis at a high current density, or small amount. of the solution will he divert by precipitating with iron. Under the action ed, or Withdrawn, to kee the solution at of the precipitant, in agitator No. l, the some standard, and this standard will usuother metals, the silver, gold, and lead, are ally be determined by the iron content, and

is quickly precipitated, While an equivalent of may range from. to l per cent iron, as e1r- 7 copper goes into solution, and all the copper pcricnce may determine for each particular in the solution will be maintained in the use. This diverted solution flowed into cuprous condition. The solution in the electrolyzer llo. f-i, where the copper-is pretutor, from which the other metals have cipitatcd out as closely as possible, proton.

l beenprecipitated, flows into separator l lo. ably with a high current (lPl'l$lii in this 1, Where the precipitated metals are sepa ay the copper is precipitated in suh-dividrated from the copper solution. The pre- (rd form, as a sponge or as granules, and this cipitute may be withdrawn from time to finely divided copper is flowed into-the pro time, as the precipitate becomes charged cipitator No. 1, Where it ma he used to prcwith other metals and the copper becomes cipitute the old, silver, and lead, tronrthe i exhausted. The clear overflowing reduced leach copper solution, Whilenn equivalent copper solution flows into electrolyzer No. of copper gocsinto solution as already do- 1, which may represent agroup of clectro-- scribed. The iinpoverished copper solution lyzers, where the copperis deposited asthe from electrolyzer No. 3, as also some of the electrolytic-metal, while acid and cupric and Wash. Water, flows into the precipitator No. 355 'ler'ric saltsare regenerated. 2, where the remaining copper is completely It the regenerated ferric and cupric salts precipitated with hydrogen sulphide.- The in theelectrolyte, due to electrolysis, exbarren solution and precipitate flow into cceds a certain small limit, say, 0.25% of separator No. L, Where the suly ihicle precipieither, or both, the cliicicncy ot' the depositate is separated from the barren solution. W i tion is greatly impaired. As soon, therc- The barren solution may be wasted, or fore, as the ferric and cupric salts exceed, fi 11150 the Qlilorlnfltor, On fillet say, a predetermined limit, fixed by new chlorinated solution tank for re-use. The periencc. the solution is again reduced with precipi a e 1S flowed, as a sludge, into the sulphur dioxide, to convert the cupric and l l'efzipitator No. l, Where the sulphidepre- 9 ferric salts into the cuprous ancl ferrous clpitate acts the same as the finely granulatconditions. The reducedsolution is then 13 1 or sponge copper to precipitate gold, sil-' again cllectmlyzedj and this p, f d .ner, and lead. lroin thc leach copper solution and electrolysis is continued until the t10'u, wh1le an eqiuvalcnt of copper goes into solution is sufficiently depicted in copper and ution. regenerated in acid, when it is .rctm'n-ctl to I The golths lrcr, and loud. also the terthe ore. It will usually be found advisable o and cupric salts formed in elcctrolyser to do this instages, so that the solution of N l d t d ti it ill fl i l; f precipi'ate, and this is continued until it ml to remove the copper tronrthc 1' closed circuit, While at the same time there becomes desirable to remove the precipitate i a p ggrgggivg advance flow through fI'Olll. ilk, lfill tlll CQPPGI SOlillTiOi'l circuit. of the electrolytic units, and finally/hack to P DIEMQ- i hdr wn. and flowed into fl -i 01-9, the (lo-cl lorlnator, where it is treated. say,

It the ore contains gold, the solution is will; y g l i WlllQll Combine-5 treated with chlorine to convert the cuprous With the insoluble chlorine, like that in the chloride and the ferrous chloride into the {01111 1 CY PIO'HS Chloride, and converts the .cupric chloride and ferric cl'iloridc, respec' copper into the sulphide, \yhile thefhlorin lively. and. is also charged with free cl'ilo- F l SOlUlll/v {1S W W h pine, "lh ol ti so tre t d, acts; dprecipitate. treated to make the insoluble so p, on th gx' ld i fl t Cmwert th chlorine soluble. then flowed into the liliutd tho chlorides and make them soluble in 3 1 it filliel-fllfiml WflSheCl 0 f it i1 1 l ti If th i -1 l org ()1 from chlorine or chlorides. Tlicuvashei'l concentrate contains considerable copper, it precipitate then roasted, and the roasted is not :uli isahlc to charge the leach solution 1"1' ip t 1S c iwl ith dilutesulphuric with chlorine until utter the copper has been acid in the agitator. The copper readily largely extra-ctetl, because, the copper is into solution as the sulphate, While the dfi amma. in an acid solution, even it gold, silver, and loud, remain insoluble. The (he copper and iron in the solution are in copper sulphate solution flows tron tlicuugrithe cuprous and ferros conditions, and it lJflLOl into the separator, Where the clear copwill be cheaper, under such circumstances, per solution overflows art-the top, and flows to first leach the larger portion of the copinto clecl'rolyzer l lo. l, "where the copper is per from the ore, than to apply free chlorine deposited electrolyically, "ithan equivalent to the solution until it becomes necessary to regeneration of acid. The regenerated acid extract the other metals. is returned to the roasted precip tate, and

' in returning the solution to the ore, n the cycle continued. until the copper is quite 13G thoroughly removed from the precipitate.

The gold, silver, and lead, are then easily" furnace is applied to the leach copper solu- I a wide field, and,

tion, as a reduclng agent, as already described.

It will be seen that this method of treating' copper ore contai iiing other metals, provides for the simultaneous extraction of all the metals with one solution, and that it prorides for the recovery of any or all of the metals in elemental form, which can be sold direct to the consumer.v

A consideration of importance in this process, using chloride solution as the solvent, will now be pointed out, and it is be lieved that this is an important factor in the consideration of leaching and electrolytic precipitation and regeneration.

It is known that carbon anodes are fairly pronounced in their depolarizing action in the deposition of copper in the presence of a suitable depolarizer, sucl as ferrous salt. lVith sulphate solutions it has been found very difficult to get sutlicient depolmizing, action to prevent the carbon anodes from disintegration, and hence, from being used on a commercial scale. Lead anodes are, therefore, ordinarily employed: but lead anodes are not pronounced in their depolarizing action, and do not appreciably reduce the voltage of copper deposition. even in the presence of a good depolarizer, such as ferrous iron.

I have found. that while carbon anodes are usually quickly disintegrated with sulphate solutions. they are but little atlccted with chloride solutions containing sulphates, such, for example, as may be formed by the use of sulphur dioxide in treating the ore or the solutions, or by roasting sulphide copper ore with salt. It is evident that this opens while 1.5 poundsirt copper, per kw.-hr. is probably the effective limit in the deposition of copper from sulphate solutions, it would be quite practical to deposit as much as 5.0 pounds, per kw.-hr., from chloride solutions, necessarily containing sulphates, when sulphur dioxide is used as a reducing agent. This can he made plain, as follows the electric current deposits twice as much copper, per ampere, from a cuprous as from a oupric solution, and the solution can be maintained largely cuprous by the use of sulphur dioxide, as employed in this process. The leach copper solution will therefore contain the copper in the. cupi'ous form, and the iron in the. ferrous form. Both cuprous copper and ferrous iron are very etlective depolarizcrs. using carbon anodes, and the voltage. of copper deposition can he maintained at. or below, if) volt.

can be deposited, per kw.hr., from cup'rous solutions, using carbon anodes, as against 1.5 pounds, with a sulphate solution, using lead, or ferrous silicon anodes. It will be observed that the circulation of the solu tion between the electrolyzers and the reducers, in a sort of closed circuit, as do scribed, with a progressive advance flow of a portion of the solution through the on tire circuit, or cycle, amply provides for] cuprrc salts 1n maintaining the ferric and the copper solution at a very low limit, or, say, 0.25 per cent',for the ample realization of the depolarization expected.

If the ore contains zinc, cobalt, nickel, etc., it is preferred to precipitate some or all of the copper and some of the other metals,

from the regular leach solution-preferably the solution to be wasted and necessarily containing some zinc cobalt and nickel" then treating the residuewith the solution and free chlorine, and then recovering all the desired metals from the resulting chloridesolution. Hydrogen sulphide is first applied to the resulting chloride solutionto precipitate the metals capable of being precipitated with hydrogen sulphide from an acid solution, and then the zinc cohalt or nickel can be recovered from the resultingsolution. Zinc cobalt or nickel, like other metals, cannot be closely extracted with a simple acid solution, but on the application of chlorine Ito the partly treated ore, the zinc cobalt and nickel may be very closely extracted. and by using" the waste solutions from the first leaching, the solution is all the while being enriched in thc' metals not precipitated by the. electric current or with hydrogen sulphide. .Metals, such as zinc, cobalt, and nickel, are all the while being: concentrated in the solution, while other metals, such as copper, are be ing eliminated, and this greatly facilitates the recovery of the cobalt and nickel.

I claim:

l. A process for treating copper ores, comprising, leaching" the ore with a chloride solution, chemically precipitating the copper from the resulting solution with the simultaneous regeneration-of acidflthen applying gaseous chlorine to the solution after precipitation, and returning the solution to the ore.

2. A process of treating'copper ores comprising, leaching the ore with a chloride solution to extract a portion of the copper,

precipitating a portion of the copper from the resulting solution electrolytically, prey cipitating a portion chemically, then applying chlorine to the depleted copper solution, and returning the solution to the ore.

3. A process of treating copper ores comleaching the ore with a chloride prising,

to extract a portion of the copper,

solution,

I rill chemically precipitating the copper from with the simultaneous the resulting solution regeneration of acid, clectrolyzing sodium chlorirlc to producc chiorinc and caustic soda and applying both the chlorine and caustic sorla to the leach solution, and rcturning; the solution to the ore" A proccss of trcatingcoppcr'orcs com- [)l'ifilllil} leaching the o1'c ,"with achloride solution to extract a portion of the copper, chemically precipitating the copper from the rcsuliing solution, and applying caustic lime to the solution to eliminatc the sulphatcs from leach solution, and returning ution to the ore. o. ii process of treating raising. leaching the orc solution to extract a copper ores comthc resulting solution clcctrolyzing sodium chloride to ,gci'ieratc chlorine and caustic soda, applying both the caustic soda and the tho resulting solution electrolytic-Lilly, pro-- clpiliatingr a portion chem cally, clcctrolym mgr sodium chloritlc to ,Q'cucra'to chlm'u'ic applying tho chlorine to tho an'rl returning the solution to the ore.

A process comprising, leaching ores of copper with a chloride solution to extract a portion of the coppcr, precipitating; ii-porliou ol' the copper from the resulting solution olcctrolytically Tilllllfl subjecting the solution to altcruato rocluction and electrolysis. precipitating: a portion of the coppcr cliciuica apply u; the chemical prcrpc clcctrolytc, applying chlorine to tho depicted copper solution, and returning the solution to'tlie ore.

9. A process of treating copper ores com prising, leaching the orc with ohloriclc solutiouto cxtract a portion oi the coppcr, precipitating a portion oi. thccopper clectrolyrically, clcclrolyziug sodium chloride to acucratc chlorinc anll austic soda. applyiu: the can tic soda to a portion of the so lutioo to pucipitatc mulcsirablc impurities, thou applylnqlhc chlorine ,to the solution roc'cucrai'crl in sodium chlorii lc anti i'cturu inc the solution to the orc.

ll). A iuctallura'ical proccss coi'uprising with a chl0ri(le' portion of the copper chemically precipitating the copper from portion of the copper,-

leach solution,-

'(llSSOlVlfnQ' the coppcr of tho treating ores of copper with anzacid solution, precipitating the copper out of the resulting solution as the sulphide, scparating the sulphide precipitate from the resultingsolution, then roasting the prccipitatclo' coni'crt tho sulphide into the oxide, and the copper from" the lhcn ro lissolving roasted prccipitato an' l clcctrolyziiu the so-'- lotion containing the rc-(lissolwd coppcr to obtain thc electrolytic metal.

11. A. metallurgical process comprising, trcatiug'coppcr orcs with an acid solution to extract the copper, prec'pitatint' .tlie copper from the leach phitlc, separating from the cipitatc to heat under rclativ'c quiescence" during the early stages of heating or roasting, re clissolving i the copper from the roasted precipitate, and elcctrolyzingthere-- solution as the sultho sulphiclc precipitate. I leach. solution, suh3cctiug the pre suiting copper solution to obtain the elcc- S5 trolytic racial. v

12. A; metallurgical process comprising,

treating-ores of copper with a solvent as the copper, chemically precipitating copper from. the resulting solution, separating the precipitate from the leach. solution, roasting the precipitate under rclatirc roasted precipitate and electrolvziug' the rc suiting copper solution to obtain tho copper as the electrolytic metal.

13. A metallurgical process comprising. treating; copper orcswith a solvent 'for the copper. precipitating resulting; solution as the sulphide, the sulphiolcpz'cci'pitato from the resulting icach solution, charging tho anoist'procio I itatc into aituruacc aucl hmitiug it sullitaicnllyf uuilcr OOIDPzlI'ItlVQ quiescence to craporatcr the moisture and ignit precipitate, con'iplcting' lhc roastcil- -prccipit-atc, and clcctrolyziugrthc;rcsultinsr solution to ohtain the electrolytic!copper.

quiescence, then rc-clissolving-the copper ot' the roasting; rcy 1 the copper from the scparating' 14. A proccss of treating" ores oi copper Q containing other metals comprising, lcacl -fling the orc with. a chloritlc solutionto o tract the metals, chcmicall-v urocipitatiug tho coppor anti other metals :l'roni the rosulting solution withnthe same roasting tho precipitatc. applviug asulphate solution (to the roasted precipitate to (lissolve the copper, clcctrolyziugrtho resulting copper solution to recover thc copper as tho GlGCllOlVllC n'ictal cmitinuing the cycle until the. copper (has been suilicicntlv removed from the roasted precipitate, and then recovering the remaining: metal values from the roasted precipitato rcsiduc.

A process of treating copper orcsconprecipitant, i

with the simultaneous iei generation of aciddeturnmg thoregcncrated c acl'cl solution to the roasted precipitate andtaining dissolving lytic metal, and

other metals comprising, leaching the ore with a chloride solution. to'ex'tract the metals, precipitating; the copper and the othe metals from the resulting leach solution with hydrogen sulphide, separating the precipitate from the leach solution, returning the solution to the ore, washing the precipitate to tree itt'rom chlorides, roasting the precipitate, applying a sulphate solution to the roasteyl precipitate to re-dissolve the copper, clolctrolyzing the resulting copper solution to deposit the copper and regenerate acidJfeturning the regenerated acid solution to the roasted precipitate, and recovering the remaining metal values from the precipitate residue.

16. A process of treating copper ores containing other metals comprising, leaching the ore with a chloride solution-to extractthe metals, precipitating a portion of the copper from the resulting solution eleetros lytically, precipitating a portion chemically, applying the chemical precipitate to the electrolyte to re-dissolve a portion of the copper from the precipitate, roasting the precipitate residue, leaching the roasted residue to remove the remaining copper, and then recovering the remaining metalvalnes from the roasted and leached residue. v

17'. A process of treating copper ores comprising, leaching the ore with a solvent "for the copper, chemically precipitating the copper from separating the copper precipitate from the solution, roasting the precipitate, then 'rethe copper with a solution relafrom injurious impurities, and clectrolyzing the resulting copper solution to ohtain the electrolytic metal.

18. A metallurgical process comprising, leaching copper ores with a solvent for the copper, precipitating the copper from the resulting solution as the sulphide, roasting the sulphide precipit te to oxidize the copper with the simultaneous liberation of sulphur dioxide,rewlissolving the copper from the roasted precipitate, electrolyzing the resulting copper solution to obtain. the electro' applying the sulphur dioxide from the roasting precipitate to the electrolytc.

, 19. A process of treating copper ores com prising. leaching the ore with a solvent for the copper. chemically precipitating the copper from the resulting leach solution, separating the copper precipitate from the solution, roasting the precipitate under relative quiescence of the particles which (10111 pose the precipitate in relation to one another, then re-dissolving the copper from the roasted precipitate with a solution relatively tree from injurious impurities, 'and electrolyzing the resulting copper solution to obtain the electrolytic metal.

tivelv tree the resulting leach solution,

' lution, then treating .20. A process of treating copper ores comprising, leaching the ore with an acid solutionto extract a portion of the copper, electrolyzing the resulting solution containing salts of iron to deposit the copper with the simultaneous regeneration of acid and ferric salts, applying copper sulphide concentrate to the electrolyzcd solutionwhereby copper is dissolved from the sulphide concentrate and the ferric salts reduced to the ferrous condition, repeating the cycle until the solution is sutiiciently copper, tion to the ore, roasting the concentrate residue still containing copper, and leaching the roasted concentrate residue with the regenerated solution formed by the electrolysis. i

21. A process of treating copper ore comprising, leaching the ore with an acid solution to extract a portion of the copper, electrolyzing the resulting copper solution containing salts of iron to deposit a portion of the copper with the simultaneous regeneration of acid, chemically precipitating another portion of the copper with the regeneration of more acid, and then returning the regenerated acid solution to the ore.

22. A process of treating copper ore containing other metals comprising, leaching the ore with a sulphate solution to extract a portion of the copper, eleetrolyzing the resulting copper sulphate solution to deposit the copper and regenerate acid, returning the regenerated acid solution to the ore an] repeating the cycle of leaching and depleted in returning the depleted copper soluelectrolysis until the copper in the ore 1s sufficiently extracted with the sulphate sosolution toextract the residual metal values,'precipitating.the metals from the chloride solution with a chemical precipitant, roasting the ing-the roasted precipitate with dilute suL phuric acid to re-dissolve the copper from the other metal values in thezprccipitate, and then recovering the residual metal values from the precipitate residue, V

23. A process of treating copper ores con taining other metals comprising, leaching the ore with a sulphate solution, electrolyzing the resulting copper sulphate solution to deposit the copper the ore and repeating and electrolysis until the copper in the ore is sufficiently extracted with the sulphate sothe ore with a chloride and regenerate acid, returning the regenerated ac'd solution tov the cycle of leaching the precipitate, then treateipitating some of the metals from the solution, then treating the ore with the resulting solution and free chlorine, precipitating some of the metals from the resulting chloride solution, separating the precipitate from the solution, and then recovering other metals from the solution.

33. A process of treating ores of metals comprising, leaching the ore with an acid,

solution to extract some of the metals, precipitating some of the metals from the solution, then treating the ore residue with the resulting solution and free chlorine to extract the remaining metals, precipitating some of the metals from the resulting chloride solution, separating the resulting precipitate from the resulting solution, and then recovering other metals from the solution.

34. A process of treating copper ores containing other metals comprising, leaching the ore with a chloride solution, apply-' ing a reducing agent to the resulting solution containing copper and other metals, electrolyzing copper solution under conditions to deposit the copper in a granular or sponge form, and applying the copper so obtained to the leach copper solution to precipitate the other metals.

35. A process of treating copper orescomprising, leaching the ore with a solution containing chlorine, precipitating the copper and other metals from the solution, treating the precipitate with a substance capable of converting insoluble chlorine into solulfle form, washing the precipitate to free it from chlorine, roasting the pie cipitate, then treating the roasted precipitate with sulphuric acid to dissolve the copper, electrolyzing the resulting copper solution to deposit the copper and regenerate acid, returning he regenerated acid solu-- tion to the precipitate, and when the copper is sufiiciently removed from the precipitate recovering the other metals from the, residue.

x 36. A process of treating copperores containing other metals comprising, leaching the ore with dilute acid solution to extract f the copper and other metals,-electrolyzing the resulting copper solution containing salts of iron and of other metals to deposit copper and regenerate acid and ferric iron, applying concentrated copper sulphide to the solution to extract'a portion of the copper from the concentrated copper sulphide with the simultaneous reduction of the terric iron formed by the electrolysis to the ferrous state and repeating the cycle of reduction and electrolysis, and then when the desired ortionof the copper has been extracted in this way from the sulphide con centrate, roastin the sulphide concentrateresidue and leaching it to extract the remetals from. the resulting solution freed from copper.

38. A process of treating copper ores containing other metals comprising, leaching the ore with a dilute acid solution to extract copper and other metals, electrolyzing the resulting copper solution containing other metals to deposit copper and regenerate acid, returning the regenerated acid solution to the ore and repeating the cycle of leaching and electrolysis to accumulate other metals in the solution in amounts to make their re-' covery from the solution desirable and from time to time recovering the other metals from the copper solution, and when the metals which'are soluble in the dilute acid so lution' are sufliciently extracted from the ore, treating the ore residue to recover other de- "siredmetals therefrom. i i

, WILLIAM GREENAWALT. 

